The present invention relates to a pump for liquid using a plurality of rotors each with a respective plurality of radially arrayed pistons in the form of hydrostatic elements with the fluid passage and delivery channels to the pistons opening laterally and particularly relates to control over the effects of lateral or axial thrust forces.
A single entry, so called side loaded hydrostatic machine or fluid pump is known from Federal Republic of Germany OS 39 05 936. Means are there provided to take up or compensate for axial thrust forces which act via the drive shaft on the radial arrangement of cylinders that define a rotor. However, it has been found that the axial forces in this connection are unfavorably high and that there are pulsating radial forces that flow back over the outer surface of the machine to the bearing points, producing undesirable loud noises. Another problem is that the bearing points for the central shaft of the machine must be very precisely aligned, which results in increased manufacturing expense.